US11532462B2 - Method and system for cleaning a process chamber - Google Patents

Abstract

Implementations disclosed herein generally relate to systems and methods of protecting a substrate support in a process chamber from cleaning fluid during a cleaning process. The method of cleaning the process chamber includes positioning in the process chamber a cover substrate above a substrate support and a process kit that separates a purge volume from a process volume. The method of cleaning includes flowing a purge gas in the purge volume to protect the substrate support and flowing a cleaning fluid to a process volume above the cover substrate, flowing the cleaning fluid in the process volume to an outer flow path, and to an exhaust outlet in the chamber body. The purge volume is maintained at a positive pressure with respect to the process volume to block the cleaning fluid from the purge volume.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent application Ser. No. 15/701,222, filed Sep. 11, 2017, which is herein incorporated by reference in its entirety.

BACKGROUNDField of the Disclosure

Implementations described herein generally relate to a method and system for cleaning a process chamber. More specifically, implementations disclosed herein relate to a method and system for manufacturing substrates in a process chamber and for cleaning the process chamber while protecting components of the process chamber from damage during the cleaning process.

Description of the Related Art

In the fabrication of integrated circuits, deposition processes such as chemical vapor deposition (CVD) or plasma enhanced CVD processes are used to deposit films of various materials upon semiconductor substrates. These depositions may take place in an enclosed process chamber. Process fluids are used to deposit films on the substrate, but also deposit residue on the internal walls and other components of the process chamber. This residue builds up as more substrates are processed in the chamber and leads to generation of particles and other contaminants. These particles and contaminants can lead to the degradation of the deposited films on the substrates causing product quality issues.

Process chambers must be periodically cleaned using a cleaning process to remove the deposited residues on the chamber components. Cleaning fluids are used during the cleaning process to clean the process chamber after substrates have been manufactured. The temperatures used in the process chamber during the processing of the substrates have been increasing to achieve better film quality for the substrates. Higher temperatures during the processing of substrates results in higher temperatures for chamber components that may be exposed to the cleaning fluid during the cleaning process.

Cleaning fluids used such as fluorine-containing reactive gases may react with chamber components to generate contaminants during the cleaning process. For example, the substrate support in the process chamber may be made of materials, including aluminum nitride, that react with the cleaning fluid to generate contaminants, including aluminum fluoride (AlF3), during the cleaning process. As the cleaning process takes place with chamber components at higher temperatures, contaminants formed due to chemical reactions with materials of the substrate support increases substantially. Cleaning contaminants also may sublimate on cooler chamber components, including a fluid distribution plate in the process chamber.

Thus, there is a need for an improved system and method for cleaning the process chamber.

SUMMARY

Implementations disclosed herein generally relate to systems and methods to prevent free radical damage to sensitive components in a process chamber and to enhance flow profiles. The process chamber utilizes a cover substrate and an inert bottom purge flow to shield the substrate support from halogen reactants such that the substrate support may be heated to temperatures greater than about 650 degrees Celsius. During a cleaning process, the cover substrate and the purge flow restricts cleaning fluid from contacting the substrate support.

In one implementation, a method of cleaning a process chamber includes positioning a cover substrate above a substrate support in an interior volume in a chamber body of the process chamber. A process kit including a top edge member and a pumping liner are disposed in the interior volume. The pumping liner separates a purge volume disposed below the cover substrate and the top edge member from an outer flow path disposed between the chamber body and the pumping liner. The method of cleaning the process chamber includes performing a cleaning process. The cleaning process includes flowing a purge gas in the purge volume. A bottom support surface and a side support surface of the substrate support are disposed in the purge volume. The cleaning process includes flowing a cleaning fluid through a fluid distribution plate to a process volume disposed between the fluid distribution plate and the cover substrate. The cleaning process includes flowing the cleaning fluid in the process volume to the outer flow path, flowing the cleaning fluid in the outer flow path to an exhaust outlet in the chamber body, and maintaining the purge volume at a positive pressure with respect to the process volume so as to block the cleaning fluid in the process volume from flowing into the purge volume.

In another implementation, a method of cleaning a process chamber includes forming a top purge barrier in an interior volume of a chamber body of the process chamber with the top purge barrier separating a process volume disposed above the top purge barrier and a purge volume disposed below the top purge barrier. The top purge barrier includes a cover substrate and a top edge member disposed above a substrate support in a spaced position. A process kit includes the top edge member and a pumping liner disposed in the interior volume. The pumping liner separates the purge volume from an outer flow path disposed between the chamber body and the pumping liner. The method of cleaning the process chamber includes performing a cleaning process. The cleaning process includes flowing a purge gas to the purge volume and from the purge volume to the process volume through a purge gap extending through the top purge barrier, and flowing a cleaning fluid from a cleaning fluid supply to the process volume disposed in the interior volume. The cleaning process further includes flowing the cleaning fluid and the purge gas from the process volume to the outer flow path through a top opening in fluid communication with the process volume, and flowing the cleaning fluid and the purge gas in the outer flow path to an exhaust outlet in fluid communication with the outer flow path and in the chamber body. The flowing of the purge gas through the purge gap blocks the cleaning fluid in the process volume from flowing to the purge volume.

In another implementation, a process chamber includes a chamber body of the process chamber having an interior volume, and the chamber body has a chamber interior surface. A substrate support disposed in the interior volume, and a process kit is disposed in the interior volume. The process kit includes a top edge member disposed outwardly from the substrate support, and a pumping liner disposed outwardly from the substrate support in the chamber body. The pumping liner surrounds a purge volume, and an outer flow path is disposed between the pumping liner and the interior chamber surface. A purge gas opening in the chamber body is in fluid communication with the purge volume. An exhaust outlet is in the chamber body, and is in fluid communication with the outer flow path. A cover substrate is disposed above the substrate support, and a purge gap is disposed between the top edge member and the cover substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective implementations.

FIG.1 is a side sectional view of a process chamber with a cover substrate in a non-spaced position, according to one implementation of the disclosure.

FIG.2 is a side sectional view of the process chamber with the cover substrate in a spaced position, according to one implementation of the disclosure.

FIG.3 is a perspective view of the process chamber with the cover substrate in the non-spaced position, according to one implementation of the disclosure.

FIG.4 is a cross-sectional schematic of the process chamber with the cover substrate in the spaced position showing flow of a cleaning fluid and a purge gas during a cleaning process, according to one implementation of the disclosure.

FIG.5 is a cross-sectional schematic of the process chamber shown inFIG.4 with the cover substrate in the non-spaced position showing flow of the cleaning fluid during the cleaning process, according to one implementation of the disclosure.

FIG.6 is a cross-sectional schematic of a process chamber with the cover substrate in the spaced position showing flow of the cleaning fluid during the cleaning process, according to an alternative implementation of the disclosure.

FIG.7 is a flow chart showing a method of cleaning the process chamber, according to one implementation of the disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one implementation may be beneficially utilized on other implementations without specific recitation.

DETAILED DESCRIPTION

Implementations disclosed herein generally relate to systems and methods to protect a substrate support from cleaning fluid used during a cleaning process of the process chamber. The process chamber utilizes a cover substrate, process kit, and the flow of purge gas to protect the substrate support from chemical reactants in the cleaning fluid. A top purge barrier in the process chamber separates a process volume disposed above the top purge barrier and a purge volume disposed below the top purge barrier. During the cleaning process, the substrate support is disposed in the purge volume and is protected from the cleaning fluid by a purge gas curtain formed by the purge gas.

FIG.1 is a side sectional view of aprocess chamber100 with acover substrate150 in a non-spaced position, according to one implementation of the disclosure. Theprocess chamber100 includes achamber body102 having achamber side wall104, achamber bottom106, and alid108 disposed on thechamber side wall104. Thechamber side wall104,chamber bottom106, andlid108 define aninterior volume110 of theprocess chamber100. Thechamber side wall104 may have an annular shape or include multiple walls to form a rectangular or square shape. Theprocess chamber100 includes afluid distribution plate112 withopenings105 and asubstrate support120. The region between thecover substrate150 in the raised position117 (FIG.1) and thefluid distribution plate112 is defined by theprocess volume109. Thefluid distribution plate112 supplies cleaning fluid from a cleaningfluid supply111 to theprocess volume109 through thefluid distribution plate112. The cleaningfluid supply111 may be a remote plasma source in some implementations. In other implementations, theprocess chamber100 may include a plasma source (e.g., a capacitively coupled plasma chamber with a RF-hot fluid distribution plate).

Thesubstrate support120 is disposed in theinterior volume110. Thesubstrate support120 may be formed of a ceramic material, such as aluminum nitride. Thesubstrate support120 may include an electrostatic chuck, a ceramic body, a heater, a vacuum chuck, a susceptor, or a combination thereof. Thesubstrate support120 has atop support surface122 that receives and supports a substrate (not shown) during a manufacturing process of the substrate. The substrate would replace thecover substrate150, shown inFIG.1 on thetop support surface122. Thesubstrate support120 further includes a bottom support surface124, and aside support surface126 disposed between the bottom support surface124 and thetop support surface122.

InFIG.1, thecover substrate150 is shown in the non-spaced position. When in the non-spaced position, thecover substrate150 is in physical contact with thetop support surface122 of thesubstrate support120. In some implementations, thesubstrate support120 has been raised to the raised position117 with thecover substrate150 in physical contact with thetop support surface122. Aprocess volume109 is disposed between thecover substrate150 and thefluid distribution plate112.

Thesubstrate support120 is coupled to a supportingshaft121 that is coupled to alift mechanism115 below thechamber bottom106 of theprocess chamber100. A bellows116 may be disposed around the portion of the supportingshaft121 that is below thechamber bottom106 of theprocess chamber100 to isolate the supportingshaft121 from the external environment. Thelift mechanism115 is configured to move thesubstrate support120 between the raised position117, as shown inFIG.1, and a loweredposition118, as shown inFIG.2. Thesubstrate support120 may be placed in the raised position117 during the manufacturing process for the substrate (not shown). In the loweredposition118, a robot or other transfer mechanism (not shown) may be used to place thecover substrate150 in theprocess chamber100. The lift pins130 extend through thesubstrate support120. A slit valve, as shown inFIG.6, may extend through thechamber side wall104 ofchamber body102 to provide an opening to transfer thecover substrate150 into or out of theinterior volume110.

A purge gas may be supplied to theprocess chamber100 during a cleaning process of theprocess chamber100. The purge gas may be supplied from apurge gas supply113 through a purge gas line114. In some implementations, the purge gas line114 may be coupled to theprocess chamber100 through thebellows116 in order to maintain a positive pressure in thebellows116 during movement of thesubstrate support120 by thelift mechanism115. The purge gas is supplied through apurge gas opening139 formed between thechamber bottom106 and the supportingshaft121. The purge gas is supplied to apurge volume180 in theprocess chamber100.

Theprocess chamber100 further includes aprocess kit140 that protects thechamber body102 from processing fluids and provides flow paths for the processing fluids. Theprocess kit140 includes apumping liner141 and atop edge member146. Thepumping liner141 surrounds thepurge volume180. Thepumping liner141 includes aside pumping liner142 and thebottom pumping plate144. In some implementations, theprocess kit140 may include anouter pumping liner152. Theouter pumping liner152 is disposed adjacent aninterior chamber surface154 of thechamber side wall104. Theside pumping liner142 is spaced radially inward from thechamber side wall104 to define anouter flow path156.

Theside pumping liner142 extends from atop end158 to abottom end160. Theside pumping liner142 is laterally spaced from theside support surface126 of thesubstrate support120 to form a substrate supportouter opening162. Theside pumping liner142 of thepumping liner141 is disposed outwardly from thesubstrate support120. Thetop end158 of theside pumping liner142 is disposed above thetop support surface122. Thebottom end160 is spaced from thechamber bottom106 and is coupled to thebottom pumping plate144. A bottom section of theouter flow path156 is defined by thebottom pumping plate144 and thechamber bottom106. Thebottom pumping plate144 extends from thebottom end160 of theside pumping liner142 to a position adjacent thepurge gas opening139. Anexhaust outlet164 extends through thechamber bottom106, and is in fluid communication with theouter flow path156. Theexhaust outlet164 may be coupled to avacuum pump165.

Thetop edge member146 of theprocess kit140 is coupled to theside pumping liner142. Thetop edge member146 includes atop surface147, abottom surface148, and aside surface149. Thetop edge member146 is vertically spaced from thetop support surface122 of thesubstrate support120. At least a portion of thetop edge member146, including theside surface149, extends over thetop support surface122 of thesubstrate support120. At least a portion of thetop edge member146 is disposed outwardly from thesubstrate support120. Apurge gap166 is disposed between thetop edge member146 and thecover substrate150. Thetop edge member146 has aside surface149 that extends over thetop support surface122. In some implementations, theside surface149 is laterally spaced from thecover substrate150 on thetop support surface122 so as to not extend over thecover substrate150.

Atop purge barrier178 is formed in theinterior volume110 of thechamber body102 above thesubstrate support120 by thecover substrate150 and thetop edge member146. Thetop purge barrier178 separates theprocess volume109 disposed above thetop purge barrier178 and apurge volume180 disposed below thetop purge barrier178. Thepumping liner141 separates thepurge volume180 from theouter flow path156 disposed between thechamber body102 and thepumping liner141. Thepurge gap166 extends through thetop purge barrier178. Thepumping liner141 further includes atop opening157 extending from the process volume into theouter flow path156 to provide fluid communication between theprocess volume109 and theouter flow path156.

InFIG.1, acontrol unit192 may be coupled to theprocess chamber100 to control processing conditions. Thecontrol unit192 comprises a central processing unit orCPU193,support circuitry194, andmemory195 containing associatedcontrol software196. Thecontrol unit192 may be one of any form of a general purpose computer processor that can be used in an industrial setting for controlling various chambers and sub-processors. TheCPU193 may use anysuitable memory195, such as random access memory, read only memory, floppy disk drive, compact disc drive, hard disk, or any other form of digital storage, local or remote. Various support circuits may be coupled to theCPU193 for supporting theprocess chamber100. Thecontrol unit192 may be coupled to another controller that is located adjacent individual chamber components. Bi-directional communications between thecontrol unit192 and various other components of theprocess chamber100 are handled through numerous signal cables collectively referred to as signal buses, some of which are shown inFIG.1.

FIG.2 is a side sectional view of theprocess chamber100 with acover substrate150 in a spaced position, according to one implementation of the disclosure. The transfer mechanism (not shown) may be used to position thecover substrate150 on the plurality of lift pins130 extending above thesubstrate support120. Thecover substrate150 has acover substrate bottom172, acover substrate top174, and a cover substrateouter surface176. Thecover substrate bottom172 is in physical engagement with the lift pins130 and is supported by the lift pins130. Each of the lift pins130 may have a lift pin bottom end that is engagement with thebottom pumping plate144. The lift pins130 are configured to move relative to thesubstrate support120 as thesubstrate support120 is raised and lowered by thelift mechanism115.

When thecover substrate150 is on the lift pins130 with thesubstrate support120 in the loweredposition118, thecover substrate150 is in the spaced position so as to be vertically separated from thetop support surface122 of thesubstrate support120. Thetop edge member146 extends over and is vertically spaced from thetop support surface122 by a vertical distance. During a cleaning process, thetop support surface122 of thesubstrate support120 may receive acover substrate150 to protect the underlyingtop support surface122 of thesubstrate support120. Thepurge volume180 includes atop purge volume288 disposed between thetop support surface122substrate support120 and the cover substrate and abottom purge volume284 disposed below thesubstrate support120. The plurality of lift pins130 provide for atop purge volume288 between thecover substrate150 and thetop support surface122 of thesubstrate support120, and abottom purge volume284.

In some implementations, thecover substrate150 may comprise a halogen resistant material. Theside surface149 is laterally spaced from the cover substrateouter surface176 to define thepurge gap166. When thecover substrate150 is in the spaced position, in some implementations the cover substrateouter surface176 opposes theside surface149 to define thepurge gap166. Thetop edge member146 forms a ring around thecover substrate150 and is planar with the cover substrate to form thetop purge barrier178 separating thetop purge volume288 from theprocess volume109 with thepurge gap166 extending through thetop purge barrier178. The lateral distance X, as shown inFIG.2, between the cover substrateouter surface176 and theside surface149 may be in a lateral distance range of 1 mm-3 mm. The vertical distance Y between thebottom surface148 of thetop edge member146 and thetop support surface122 may be in a vertical distance range of 1 mm to 8 mm.

FIG.3 is a perspective view of theprocess chamber100 ofFIG.2. Theside pumping liner142 of thepumping liner141 may be disposed adjacent theinterior chamber surface154. Theside pumping liner142 surrounds thepurge volume180. As shown inFIG.3, theside pumping liner142 and thetop edge member146 each have an annular shape. Thetop edge member146 forms an edge ring that surrounds thecover substrate150. Theside pumping liner142 is disposed around thesubstrate support120 to separate thepurge volume180 from theouter flow path156. Thetop edge member146 forms a ring around thecover substrate150. The slit valve (not shown) may extend through a portion of thechamber body102 and theside pumping liner142.

FIG.4 is a cross-sectional schematic of theprocess chamber100 showing flow of a cleaning fluid during a cleaning process, according to one implementation of the disclosure. The operation ofprocess chamber100 includes a cleaning process for cleaning theprocess chamber100 with a cleaning fluid. The cleaning fluid may be a fluorine-containing reactive gas. For example, the cleaning fluid may include nitrogen fluoride (NF₃). The cleaning fluid may be supplied to theprocess volume109 of theprocess chamber100 by the cleaningfluid supply111, which may be a remote plasma source. The cleaningfluid supply111 is coupled to thefluid distribution plate112 for supplying the cleaning gas to theprocess volume109. The cleaning gas may include fluorine radicals. Theprocess kit140 helps control the flow of the cleaning fluid in theinterior volume110 and control what portions of theinterior volume110 that the cleaning fluid flows through.

Theprocess kit140 is configured to control the flow profile through theprocess chamber100 in order to protect thesubstrate support120 from the cleaning fluid. A purge gas is used together with theprocess kit140 to generate a purge gas curtain that blocks the cleaning fluid from contacting thesubstrate support120 during the cleaning process. The purge gas curtain prevents the cleaning fluid from reaching thesubstrate support120 and reacting with the substrate support material and forming contaminants in theprocess chamber100.

As shown inFIG.4, thesubstrate support120 is in the loweredposition118. Thecover substrate150 is in the spaced position and is supported by the lift pins130. The purge gas in combination with theprocess kit140 protects thesubstrate support120 by placing a fluid curtain that blocks the cleaning fluid from coming into contact with thesubstrate support120. By way of example only, the purge gas may include inert gases and/or O₂, among others. In one implementation, the purge gas may be argon. Thepurge volume180 is defined by theside pumping liner142, thebottom pumping plate144, thetop edge member146 and thecover substrate150. In the implementation shown inFIG.4, thepurge volume180 includes thetop purge volume288 disposed below thecover substrate150 andtop edge member146 and above thesubstrate support120. Thepurge volume180 further includes abottom purge volume284 disposed below thetop purge barrier178 and above thebottom pumping plate144.

In the cleaning process, the purge gas flows in thebottom purge volume284 from thepurge gas opening139 extending through theprocess chamber100. In some implementations, during an initial purging process the purge gas is pumped intopurge volume180 prior to the cleaning fluid being pumped into theprocess volume109. The initial purging process may be performed in theprocess chamber100 before performing the cleaning process. In one implementation, the flowing of the purge gas to thepurge volume180 starts before the flowing of the cleaning fluid through thefluid distribution plate112 to theprocess volume109 during the cleaning process. The purge gas forms a fluid curtain around thesubstrate support120. The flow of the purge gas is shown bypurge arrows400 flowing frompurge gas opening139 into thebottom purge volume284. The purge gas is shown bypurge arrows400 flowing through the substrate supportouter opening162 to thebottom purge volume284, through the substrate supportouter opening162 and to thetop purge volume288. Thetop purge volume288 ofpurge volume180 is in fluid communication with theprocess volume109, and the purge gas flows from thetop purge volume288 to theprocess volume109 throughpurge gap166. The purge gas may then flow to theouter flow path156 and throughexhaust outlet164. Thevacuum pump165 may be used to pump the purge gas through theouter flow path156 to theexhaust outlet164. Thepurge volume180 is maintained at a positive pressure with respect to theprocess volume109 so that purge gas flows from thepurge volume180 to theprocess volume109. The positive pressure is maintained in thetop purge volume288 so that purge gas flows through thepurge gap166 to block cleaning fluid from flowing from theprocess volume109 through thetop purge barrier178 to thetop purge volume288. In other words, the pressure in thepurge volume180 is greater than the pressure in theprocess volume109 during the cleaning process.

While flowing the purge gas through thepurge volume180 and to theprocess volume109, the cleaning process starts. The flowing of the cleaning fluid to theprocess volume109, in some embodiments, includes starting to flow the cleaning fluid through thefluid distribution plate112 from the cleaningfluid supply111 while theprocess volume109 contains purge gas from the initial purging process. In the cleaning process, the cleaning fluid flows into theprocess volume109 by flowing cleaning fluid through thefluid distribution plate112, as depicted by cleaningfluid arrows402. In some implementations, the cleaning fluid is supplied by the cleaningfluid supply111, which in some embodiments may be a remote plasma source. The cleaning fluid from theprocess volume109 and purge gas that flows into theprocess volume109 from thepurge volume180 flows to theouter flow path156 and out theexhaust outlet164, as depicted byexhaust arrows404. Thepumping liner141 separates thepurge volume180 disposed below thecover substrate150 and thetop edge member146 from theouter flow path156 disposed between thechamber body102 and thepumping liner141.

The cleaning fluid flows out of theprocess chamber100 through theexhaust outlet164. Thecover substrate150 and thetop edge member146 form thetop purge barrier178 that blocks the cleaning fluid from thepurge volume180 and thesubstrate support120 disposed in thepurge volume180.Purge volume180 is maintained at a positive pressure with respect to theprocess volume109. The positive pressure has the benefit of stopping or reducing the contact of the cleaning fluid with thesubstrate support120 during the cleaning process.

In some implementations, after the cleaning process a post cleaning process starts. During the post cleaning phase, the flow of cleaning fluid through thefluid distribution plate112 stops and the purge gas continues to be supplied to theprocess chamber100. The purge gas continues to be supplied to thepurge volume180 of theprocess chamber100 for a selected time period after stopping the flow of process gas to theprocess volume109 during the cleaning process. The selected time period is an amount of time selected to remove cleaning fluid from theprocess volume109 supplied during the cleaning process.

After the cleaning process and the post cleaning process, thecover substrate150 may be removed from theprocess volume109. Theprocess chamber100 is then ready for a substrate to be transferred into theprocess chamber100 by transferring the substrate through theslit valve638, shown inFIG.6, and above thesubstrate support120. The substrate may be placed on the lift pins130 or in physical contact with thetop support surface122 by a transfer mechanism (not shown) in a conventional manner. A deposition process may then be performed on the substrate by flowing process gas through thefluid distribution plate112 to deposit one or more layers on the substrate. The process gas flows through theouter flow path156 to theexhaust outlet164. After a number of substrates have been processed in theprocess chamber100, a cleaning process as described with respect toFIG.4 may be performed.

FIG.5 is a cross-sectional schematic of theprocess chamber100 shown inFIG.4 with thecover substrate150 in a non-spaced position showing flow of a cleaning fluid during the cleaning process, according to one implementation of the disclosure. The cleaning process for theprocess chamber100 operates in a similar manner as described with respect toFIG.4. Thecover substrate150 is in physical contact with thetop support surface122 of thesubstrate support120. In some implementations, thesubstrate support120 has been raised to the raised position117 with thecover substrate150 in physical contact with thetop support surface122. Thecover substrate150 protects thetop support surface122 of thesubstrate support120 by being in physical contact with the substrate support. Thepurge volume180 is disposed below thetop purge barrier178 formed by thetop edge member146 and thesubstrate support120.

During the cleaning process, the purge gas flows into thepurge volume180 so that the purge gas in thepurge volume180 is at a positive pressure relative to the process gas in theprocess volume109. In some implementations, thetop edge member146 is disposed above thetop support surface122 of thesubstrate support120. In other implementations, thetop edge member146 opposes thecover substrate150 in a manner as described with respect to theprocess chamber100 shown inFIG.4. Thepurge gap166 is selected to maintain a positive pressure in thepurge volume180 during the cleaning process. The flowing of the purge gas through thepurge gap166 blocks the cleaning fluid in theprocess volume109 from flowing to thepurge volume180. Theprocess volume109 and thepurge volume180 are maintained at a vacuum relative to the ambient pressure external of theprocess chamber100.

FIG.6 is a cross-sectional schematic of aprocess chamber600 with thecover substrate150 in the spaced position showing flow of a cleaning fluid during a cleaning process. Theprocess chamber600 is similar to theprocess chamber100 with differences described herein. Theprocess chamber600 includes aprocess kit640. Theprocess kit640 includes apumping liner641 and atop edge member646. Thepumping liner641 includes aside pumping liner642, a firstbottom pumping plate644, and a secondbottom pumping plate645. Theside pumping liner642 surrounds thesubstrate support120. Theside pumping liner642 includes a linertop end658 that is disposed above thesubstrate support120. Thepumping liner641 may function as a radiation shield so as to shield thechamber side wall104 from heat radiated from thesubstrate support120. Aslit valve638 may extend through thechamber side wall104 ofchamber body102 to provide an opening to transfer a substrate orcover substrate150 into or out of theprocess volume109. Theslit valve638 is closed during the cleaning process.

Theside pumping liner642, the firstbottom pumping plate644,top edge member646, and thecover substrate150 define thepurge volume680. Thepurge volume680 includes atop purge volume688 and abottom purge volume684. Thetop purge volume688 is disposed below thecover substrate150 andtop edge member646 and above thesubstrate support120. Thebottom purge volume684 is disposed below thesubstrate support120, above the firstbottom pumping plate644, and within theside pumping liner642.

The secondbottom pumping plate645 extends from thechamber side wall104 and is spaced below the firstbottom pumping plate644. Anouter flow path656 is disposed between theside pumping liner642 and thechamber side wall104, and between the firstbottom pumping plate644 and the secondbottom pumping plate645.

Thetop edge member646 surrounds thecover substrate150. Thetop edge member646 is coupled to thechamber side wall104, and extends from thechamber side wall104 to extend over thesubstrate support120. Thetop edge member646 has atop opening657 that extends through thetop edge member646. Thetop opening657 is disposed above theouter flow path656. Thetop edge member646 has aside surface649. Thetop edge member646 extends over thesubstrate support120. Theside surface649 is laterally spaced from thecover substrate150 to form thepurge gap166. In some implementations, when thecover substrate150 is in the spaced position, as shown inFIG.6, the cover substrateouter surface176 opposes theside surface149 to define thepurge gap166. An outer path opening655 opens from thetop purge volume688 ofpurge volume680 to theouter flow path656. The outer path opening655 is defined by the linertop end658 and thetop edge member646.

A purge gas isolates thesubstrate support120 during the cleaning process. During the cleaning process, the purge gas flows into thebottom purge volume684, as shown bypurge arrows400. Thepurge volume680 is at a positive pressure relative to theprocess volume109. The positive pressure in thepurge volume680 is maintained when cleaning fluid flows into the process volume from thefluid distribution plate112. As shown by thepurge arrows400, the purge gas flows into theouter flow path656 through the outer path opening655. In addition, the purge gas flows to theprocess volume109 through thepurge gap166. Cleaning fluid flowing from thefluid distribution plate112 is depicted by cleaningfluid arrows402, and cleaning fluid is shown flowing to theprocess volume109, through thetop opening657, throughouter flow path656, and throughexhaust outlet164.

FIG.7 is a flow chart showing a method of cleaning theprocess chamber100,600. Thecleaning method700 includes positioning thecover substrate150 atblock702 above asubstrate support120 in aninterior volume110 in achamber body102. Thecleaning method700 includes performing a cleaning process that provides for flowing a purge gas into thepurge volume180 atblock704. The bottom support surface124 and theside support surface126 of thesubstrate support120 are disposed in thepurge volume180.

Atblock706, the cleaning process includes flowing the cleaning fluid through thefluid distribution plate112 to theprocess volume109 disposed betweenfluid distribution plate112 and thecover substrate150. The flowing of the purge gas to thepurge volume180 and the flowing of the cleaning fluid from the cleaningfluid supply111 to theprocess volume109 occurs simultaneously during at least a portion of the cleaning process. In some embodiments, the flowing of the purge gas to thepurge volume180 starts before the flowing of the cleaning fluid through thefluid distribution plate112 to theprocess volume109 during the cleaning process. The flowing of the purge gas to thepurge volume180 and the flowing of the cleaning fluid from the cleaningfluid supply111 to theprocess volume109 occurs simultaneously during the cleaning process.

The cleaning fluid in theprocess volume109 flows, atblock708, to theouter flow path156, and atblock710 the cleaning fluid flows in theouter flow path156 to theexhaust outlet164 in thechamber body102. Atblock712, the cleaning fluid in theprocess volume109 is blocked from flowing to thepurge volume180 by maintaining thepurge volume180 at a positive pressure with respect to theprocess volume109.

Benefits of the disclosure include the shielding of thesubstrate support120 from the cleaning fluid to prevent or reduce the formation of contaminants due to cleaning fluid reaction with aluminum nitride or other materials of thesubstrate support120 during the cleaning process. The shielding of thesubstrate support120 helps prevent the substantial contaminants that may form in theprocess chamber100,600 when thesubstrate support120 is at a high temperature. Thesubstrate support120 may be at a high temperature due to use of the process chamber to manufacture substrates at processing temperatures equal to or greater than 650 degrees Celsius.

To summarize, the implementations disclosed herein relate to acover substrate150 on lift pins130 that protect asubstrate support120 in aprocess chamber100,600 during cleaning. Theprocess chamber100,600 utilizes an inert bottom purge flow to shield thesubstrate support120 from cleaning fluids such that thesubstrate support120 may be heated to temperatures greater than about 650 degrees Celsius. Additionally, thetop purge barrier178 direct and control the flow profile of the cleaning fluid away from thesubstrate support120, such that free radical damage does not occur on thesubstrate support120.

While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (20)

What is claimed is:

1. A process chamber, comprising:

a chamber body having an interior volume, wherein the chamber body has an interior chamber surface;

a substrate support disposed in the interior volume;

a process kit disposed in the interior volume, comprising:

a pumping liner disposed outwardly from the substrate support, the pumping liner surrounding a purge volume;

a top edge member coupled to the pumping liner and at least partially disposed over and vertically spaced from the substrate support; and

an outer flow path disposed between the pumping liner and the interior chamber surface;

a purge gas opening in the chamber body in fluid communication with the purge volume;

an exhaust outlet in the chamber body, the exhaust outlet in fluid communication with the outer flow path;

a cover substrate disposed above the substrate support; and

a control unit configured to:

cause the cover substrate to be actuated to a spaced position wherein the cover substrate is vertically spaced from the substrate support and horizontally spaced from and planar with the top edge member; and

while the cover substrate is in the spaced position, cause purge gas to flow into the purge volume.

2. The process chamber ofclaim 1, wherein the top edge member has a side surface, wherein the cover substrate has a cover substrate outer surface, and wherein a purge gap is formed between the side surface and the cover substrate outer surface.

3. The process chamber ofclaim 2, wherein the purge gap has a lateral distance ranging between about 1 mm and about 3 mm.

4. The process chamber ofclaim 1, wherein the pumping liner further comprises:

a bottom pumping plate laterally extending from a position adjacent the purge gas opening to a position adjacent the outer flow path, a bottom section of the outer flow path partially defined by the bottom pumping plate; and

an annular side pumping liner laterally spaced from the substrate support, extending from a bottom end to a top end of the pumping liner, and coupled, at the bottom end, to the bottom pumping plate.

5. The process chamber ofclaim 4, wherein top edge member is coupled to the side pumping liner at the top end and extends inward therefrom.

6. The process chamber ofclaim 4, wherein the pumping liner further comprises:

an outer pumping liner disposed radially outward of the side pumping liner and radially inward of a chamber side wall, the outer pumping liner partially defining the outer flow path.

7. The process chamber ofclaim 1, further comprising a plurality of lift pins configured to actuate the cover substrate between a non-spaced position and the spaced position relative to the substrate support, wherein the cover substrate is in physical contact with a top surface of the substrate support in the non-spaced position, and wherein a top purge volume is disposed between the cover substrate and the substrate support in the spaced position.

8. The process chamber ofclaim 1, further comprising a lift mechanism coupled to the substrate support and configured to actuate the substrate support between a lowered position and a raised position.

9. The process chamber ofclaim 8, wherein a distance between a bottom surface of the top edge member and a top surface of the substrate support in the lowered position is between about 1 mm and about 8 mm.

10. The process chamber ofclaim 4, wherein the bottom end of the pumping liner is spaced apart from a bottom of the chamber body.

11. A process chamber, comprising:

a chamber body having an interior volume, wherein the chamber body has an interior chamber surface;

a substrate support disposed in the interior volume;

a process kit disposed in the interior volume, comprising:

a pumping liner disposed outwardly from the substrate support and surrounding a purge volume, the pumping liner comprising a top end disposed above the substrate support and a bottom end disposed below the substrate support;

a top edge member coupled to a top end of the pumping liner and at least partially disposed over and vertically spaced from the substrate support; and

an outer flow path disposed between the pumping liner and the interior chamber surface;

a purge gas opening in the chamber body in fluid communication with the purge volume;

an exhaust outlet in the chamber body, the exhaust outlet in fluid communication with the outer flow path;

a cover substrate disposed above the substrate support; and

a control unit configured to:

cause the cover substrate to be actuated to a spaced position wherein the cover substrate is vertically spaced from the substrate support and horizontally spaced from and planar with the top edge member; and

while the cover substrate is in the spaced position, cause purge gas to flow into the purge volume.

12. The process chamber ofclaim 11, wherein the top edge member has a side surface, wherein the cover substrate has a cover substrate outer surface, and wherein a purge gap is formed between the side surface and the cover substrate outer surface.

13. The process chamber ofclaim 11, wherein the pumping liner further comprises:

a bottom pumping plate laterally extending from a position adjacent the purge gas opening to a position adjacent the outer flow path, a bottom section of the outer flow path partially defined by the bottom pumping plate; and

an annular side pumping liner laterally spaced from the substrate support, extending from the bottom end to the top end of the pumping liner, and coupled, at the bottom end, to the bottom pumping plate.

14. The process chamber ofclaim 13, wherein top edge member extends inward from the top end of the pumping liner.

15. The process chamber ofclaim 13, wherein the pumping liner further comprises:

an outer pumping liner disposed radially outward of the side pumping liner and radially inward of a chamber side wall, the outer pumping liner partially defining the outer flow path.

16. The process chamber ofclaim 13, wherein the bottom end of the pumping liner is spaced apart from a bottom of the chamber body.

17. The process chamber ofclaim 11, further comprising a plurality of lift pins configured to actuate the cover substrate between a non-spaced position and the spaced position relative to the substrate support, wherein the cover substrate is in physical contact with a top surface of the substrate support in the non-spaced position, and wherein a top purge volume is disposed between the cover substrate and the substrate support in the spaced position.

18. The process chamber ofclaim 11, further comprising a lift mechanism coupled to the substrate support and configured to actuate the substrate support between a lowered position and a raised position.

19. A process chamber, comprising:

a chamber body having an interior volume, wherein the chamber body has an interior chamber surface;

a substrate support disposed in the interior volume;

a process kit disposed in the interior volume, comprising:

a pumping liner disposed outwardly from the substrate support and surrounding a purge volume, the pumping liner comprising a top end disposed above the substrate support and a bottom end disposed below the substrate support, the pumping liner and the interior chamber surface at least partially forming an outer flow path; and

a top edge member coupled to a top end of the pumping liner and at least partially disposed over and vertically spaced from the substrate support;

a cover substrate disposed above the substrate support; and

a control unit configured to:

cause the cover substrate to be actuated to a spaced position wherein the cover substrate is vertically spaced from the substrate support and horizontally spaced from and planar with the top edge member; and

while the cover substrate is in the spaced position, cause purge gas to flow into the purge volume.

20. The process chamber ofclaim 19, wherein the pumping liner further comprises:

a bottom pumping plate laterally extending from a position adjacent to a purge gas opening in the chamber body to a position adjacent the outer flow path, a bottom section of the outer flow path partially defined by the bottom pumping plate; and

an annular side pumping liner laterally spaced from the substrate support, extending from the bottom end to the top end of the pumping liner, and coupled, at the bottom end, to the bottom pumping plate.

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